Exploding star coming to a telescope near you

Over the next few days, those of us in the northern hemisphere will have the rare chance to watch a star explode - hopefully via nothing more than a small telescope.

A supernova has been spotted in a nearby galaxy, located in the Ursa Major constellation, a find that might even help the study of dark energy. An automated telescope detected the blast on 25 August as part of the Palomar Transient Factory sky survey.

The explosion is taking place about 25 million light years from Earth, in a spiral galaxy called the Pinwheel, also known as M101. It is still increasing in brightness, and may eventually be visible with small telescopes.

The new supernova, called PTF11kly, is a member of a particularly interesting class called Type Ia. These occur when a white dwarf star tears itself to bits in a nuclear explosion.

PTF11kly
is the closest Type Ia observed since 1972, providing a rare
opportunity to see the anatomy of this kind of event up close, and
perhaps better understand the stars that produce them, as explained on the Bad Astronomy blog.

There have been closer supernovas of other types since then. Most notably, 24 years ago, supernova 1987A could be seen erupting just 170,000 light years away and was visible to the naked eye.
It was a Type II-P, resulting from the collapse of a massive star into a
neutron star or black hole.

The new supernova is not expected to
be visible to the naked eye. But Mark Sullivan of the University of
Oxford, a member of the survey team that discovered the supernova, told Nature that the supernova could reach magnitude 9 or 10 in brightness in early September.

For comparison, the planet Neptune is 2.5 to 6 times as bright as this. Sky & Telescope describes Neptune
as "visible in steadily-supported binoculars, but only if you look
quite carefully". Given how much fainter PTF11kly will be even at its
peak, it will probably require a telescope to see.

Even so,
it is an exciting event that is getting brighter by the day, and it may
help us learn more about dark energy, if only indirectly. Stay tuned.

The fact that this 'explosion' took place 25 million years ago as well as being very far away makes it more remarkable.
Let's just pray this kind of event doesn't happen somewhere too close in our galaxy.
End of the world anyone?